Rub chicken pieces with lemon juice and set aside to marinate for 20 minutes; season well with salt and pepper. Heat butter and oil in Dutch oven or large heavy saucepan. Saute chicken pieces with chopped onion and carrots until lightly golden but not brown. Add tarragon and enough wine to cover. Bring to a boil. Reduce heat and simmer until chicken is tender.

Remove chicken and keep warm. Skim fat from sauce and boil until thickened and reduced to about one cup. Add mushrooms and cook for a minute or two longer. Serve mushroom sauce over chicken. Sprinkle with chopped parsley.